What is required if one of the houses of Congress want to conduct business in another location other than the Capital Building?

Stuck on this question! Please help.
Answers

Judith

I'm sure many a deal has been reached over a dinner table in a fine restaurant - or in their congressional offices before being voted upon when congress is in session.

Nick

I believe there are Constitutional issues there.

John

Not sure, maybe a Constitutional Convention, or an earthquake.